Preparation and surface characteristics of Re                         3                         W matrix scandate cathode: An experimental and theoretical study

Chen Lai; Jinshu Wang; Fan Zhou; Wei Liu; Peng Hu; Changhao Wang; Ruzhi Wang; Naihua Miao

doi:10.1016/j.apsusc.2018.01.169

Preparation and surface characteristics of Re ₃ W matrix scandate cathode: An experimental and theoretical study

Chen Lai
, Jinshu Wang^*
, Fan Zhou
, Wei Liu
, Peng Hu
, Changhao Wang
, Ruzhi Wang
, Naihua Miao

^*Corresponding author for this work

School of Materials Science and Engineering

Beijing University of Technology

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

The Scandia doped thermionic cathodes have received great attention owing to their high electron emission density in past two decades. Here, Scandia doped Re ₃ W matrix scandate (RS) cathodes are fabricated by using Sc ₂ O ₃ doped Re ₃ W powders that prepared by spray drying method. The micromorphology, surface composition and chemical states of RS cathode are investigated with various modern technologies. It reveals that the reduction temperature of RS powders is dramatically increased by Sc ₂ O ₃ . On the surface of RS cathode, a certain amount of Sc ₂ O ₃ nanoparticles and barium salt submicron particles are observed. According to the in situ Auger electron spectroscopy analysis, the concentration ratio of Ba:Sc:O is determined to be 2.9:1.1:2.7. The X-ray photoelectron spectroscopy data indicates that low oxidation state of Sc is clearly observed in scandate cathodes. The high atomic ratio of Ba on RS cathode surface is suggested due to the high adsorption of Re ₃ W to Ba. Moreover, RS cathode shows better adsorption to Sc by comparison with conventional tungsten matrix scandate cathode. For RS cathode, the main depletion of Sc is suggested to -OSc desorbing from RS cathode surface. RS cathode is expected to be an impressive thermionic cathode with good emission properties and ion anti-bombarding insensitivity.

Original language	English
Pages (from-to)	763-769
Number of pages	7
Journal	Applied Surface Science
Volume	440
DOIs	https://doi.org/10.1016/j.apsusc.2018.01.169
State	Published - 15 May 2018

Keywords

Density functional theory
Desorption
Re W matrix
Scandate cathode

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@article{01976c4f186d4c68a892ac00bc13f7c9,

title = "Preparation and surface characteristics of Re 3 W matrix scandate cathode: An experimental and theoretical study",

abstract = " The Scandia doped thermionic cathodes have received great attention owing to their high electron emission density in past two decades. Here, Scandia doped Re 3 W matrix scandate (RS) cathodes are fabricated by using Sc 2 O 3 doped Re 3 W powders that prepared by spray drying method. The micromorphology, surface composition and chemical states of RS cathode are investigated with various modern technologies. It reveals that the reduction temperature of RS powders is dramatically increased by Sc 2 O 3 . On the surface of RS cathode, a certain amount of Sc 2 O 3 nanoparticles and barium salt submicron particles are observed. According to the in situ Auger electron spectroscopy analysis, the concentration ratio of Ba:Sc:O is determined to be 2.9:1.1:2.7. The X-ray photoelectron spectroscopy data indicates that low oxidation state of Sc is clearly observed in scandate cathodes. The high atomic ratio of Ba on RS cathode surface is suggested due to the high adsorption of Re 3 W to Ba. Moreover, RS cathode shows better adsorption to Sc by comparison with conventional tungsten matrix scandate cathode. For RS cathode, the main depletion of Sc is suggested to -OSc desorbing from RS cathode surface. RS cathode is expected to be an impressive thermionic cathode with good emission properties and ion anti-bombarding insensitivity.",

keywords = "Density functional theory, Desorption, Re W matrix, Scandate cathode",

author = "Chen Lai and Jinshu Wang and Fan Zhou and Wei Liu and Peng Hu and Changhao Wang and Ruzhi Wang and Naihua Miao",

note = "Publisher Copyright: {\textcopyright} 2018 Elsevier B.V.",

year = "2018",

month = may,

day = "15",

doi = "10.1016/j.apsusc.2018.01.169",

language = "英语",

volume = "440",

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journal = "Applied Surface Science",

issn = "0169-4332",

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TY - JOUR

T1 - Preparation and surface characteristics of Re 3 W matrix scandate cathode

T2 - An experimental and theoretical study

AU - Lai, Chen

AU - Wang, Jinshu

AU - Zhou, Fan

AU - Liu, Wei

AU - Hu, Peng

AU - Wang, Changhao

AU - Wang, Ruzhi

AU - Miao, Naihua

PY - 2018/5/15

Y1 - 2018/5/15

N2 - The Scandia doped thermionic cathodes have received great attention owing to their high electron emission density in past two decades. Here, Scandia doped Re 3 W matrix scandate (RS) cathodes are fabricated by using Sc 2 O 3 doped Re 3 W powders that prepared by spray drying method. The micromorphology, surface composition and chemical states of RS cathode are investigated with various modern technologies. It reveals that the reduction temperature of RS powders is dramatically increased by Sc 2 O 3 . On the surface of RS cathode, a certain amount of Sc 2 O 3 nanoparticles and barium salt submicron particles are observed. According to the in situ Auger electron spectroscopy analysis, the concentration ratio of Ba:Sc:O is determined to be 2.9:1.1:2.7. The X-ray photoelectron spectroscopy data indicates that low oxidation state of Sc is clearly observed in scandate cathodes. The high atomic ratio of Ba on RS cathode surface is suggested due to the high adsorption of Re 3 W to Ba. Moreover, RS cathode shows better adsorption to Sc by comparison with conventional tungsten matrix scandate cathode. For RS cathode, the main depletion of Sc is suggested to -OSc desorbing from RS cathode surface. RS cathode is expected to be an impressive thermionic cathode with good emission properties and ion anti-bombarding insensitivity.

AB - The Scandia doped thermionic cathodes have received great attention owing to their high electron emission density in past two decades. Here, Scandia doped Re 3 W matrix scandate (RS) cathodes are fabricated by using Sc 2 O 3 doped Re 3 W powders that prepared by spray drying method. The micromorphology, surface composition and chemical states of RS cathode are investigated with various modern technologies. It reveals that the reduction temperature of RS powders is dramatically increased by Sc 2 O 3 . On the surface of RS cathode, a certain amount of Sc 2 O 3 nanoparticles and barium salt submicron particles are observed. According to the in situ Auger electron spectroscopy analysis, the concentration ratio of Ba:Sc:O is determined to be 2.9:1.1:2.7. The X-ray photoelectron spectroscopy data indicates that low oxidation state of Sc is clearly observed in scandate cathodes. The high atomic ratio of Ba on RS cathode surface is suggested due to the high adsorption of Re 3 W to Ba. Moreover, RS cathode shows better adsorption to Sc by comparison with conventional tungsten matrix scandate cathode. For RS cathode, the main depletion of Sc is suggested to -OSc desorbing from RS cathode surface. RS cathode is expected to be an impressive thermionic cathode with good emission properties and ion anti-bombarding insensitivity.

KW - Density functional theory

KW - Desorption

KW - Re W matrix

KW - Scandate cathode

UR - https://www.scopus.com/pages/publications/85041379351

U2 - 10.1016/j.apsusc.2018.01.169

DO - 10.1016/j.apsusc.2018.01.169

M3 - 文章

AN - SCOPUS:85041379351

SN - 0169-4332

VL - 440

SP - 763

EP - 769

JO - Applied Surface Science

JF - Applied Surface Science

ER -

Preparation and surface characteristics of Re ₃ W matrix scandate cathode: An experimental and theoretical study

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Keywords

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